This is the second year of a three year grant. Investigations in the coming year will be related to elucidating the cochlear site and mechanism of ototoxic action of the "loop" diuretics in cats and guinea pigs. BIBLIOGRAPHIC REFERENCE: Brown, R.D. Changes in Cochlear Microphonics (CM) and N1 of the Cat Produced by Intravenous Bumetanide. Federation Proceedings 35 (1976), 2291 (Abs.). Brown, R.D. Changes in the Cochlear Microphonics (CM) and N1 of the Guinea Pig Produced by Intravenous Bumetanide, The Pharmacologist 18 (1976), (Abs.).